These little connectors are perfect for connecting Foam core board sheets together, and also for connecting Foam core board to a wood table top.
I use these
...さらに表示 connectors to build a temperature shelter around my 3D printer. The OpenScad file has been included to allow you to customize your own sizes. Edit the two values near the top of the SCAD file as required.
The pre-built STL files are pre-set for 4.8mm dollar tree foam board and 7/16" plywood table top thicknesses.
Enjoy the inexpensive flexibility of foam core board.